1. Field of the Invention
The present invention relates to an apparatus and a method for reproducing a disc, and more particularly to those capable of detecting a face-down state of a disc.
2. Description of the Related Art
FIG. 11 shows a sectional structure of a CD (Compact Disc). As illustrated in this diagram, an information recording layer 2 is formed on a base 1, and a protective film 3 is formed on the information recording layer 2. The thickness of the base 1 is sufficiently greater than that of the protective film 3. And the information recorded in the layer 2 is reproduced by irradiation of a laser beam from the side of the base 1.
FIG. 12 shows a sectional structure of an exemplary DVD (Digital Versatile Disc) where merely a single information recording layer is formed. As illustrated, an information recording layer 12 is formed on a protective film 11, and another protective film 13 is formed on the information recording layer 12. The two protective films 11 and 13 are so formed as to be substantially the same in thickness. And the information can be reproduced by irradiation of a laser beam from the side of the protective film 11.
Since the protective film 3 is sufficiently thinner than the base 1 as shown in FIG. 11, if a CD is placed in a face-down state, it is impossible to read out the recorded information in the layer 2 even by irradiation of a laser beam from the side of the protective film 3.
Meanwhile, in the case of a DVD where the protective films 11 and 13 are substantially the same in thickness, when a user erroneously places a DVD as illustrated in FIG. 13 for example where the protective film 13 is turned opposite to a pickup, it is possible in principle to read out the recorded information in the layer 12 by irradiation of a laser beam from the side of the protective film 13 if no label or the like is stuck on the protective film 13. In this case, however, proper data fail to be obtained, and the user may misconceive that the DVD is a damaged one.